JP2947519B2 - Photosensitive lithographic printing plate - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a photosensitive lithographic printing plate, and more particularly, to a photosensitive lithographic printing plate containing a naphthoquinonediazide compound as a photosensitive component.

BACKGROUND OF THE INVENTION In general, a positive photosensitive lithographic printing plate is one in which an ink receptive photosensitive layer which is solubilized by exposure to actinic rays such as ultraviolet rays is formed on a hydrophilic support. When the photosensitive layer is subjected to image exposure and development, the non-image part is removed leaving the image part, and an image is formed. In lithographic printing, a difference in properties between the lipophilic image portion and the non-image portion being hydrophilic is used.

Usually, the photosensitive layer of the positive photosensitive lithographic printing plate contains an o-quinonediazide compound as a photosensitive component, and among the above-mentioned o-quinonediazide compounds, 1,2-naphthoquinone-2 is preferred from the viewpoint of sensitivity and cost. -Diazide-
5-Sulfonate compounds are commonly used as useful.

Conventionally, development processing of such a positive type photosensitive lithographic printing plate is usually performed in a developing solution composed of an alkaline aqueous solution. However, the developing ability of the developing solution is easily changed under various conditions. In some cases, the photosensitive layer in the non-image area of the printing plate may not be completely dissolved even after processing, due to deterioration of the developing ability due to deterioration due to heat or air oxidation. For this reason, it is desired that the photosensitive lithographic printing plate has a wide development allowance that shows the same developability as the case of processing with a standard developer, even in a developer having a reduced processing ability as described above.
(Hereinafter, the permissible range of a decrease in the developing ability at which an appropriate development result can be obtained is referred to as under developability.) On the other hand, a photosensitive lithographic printing plate having high sensitivity is required for improving workability and the like. The sensitivity of the photosensitive lithographic printing plate is still insufficient, and therefore, the amount of the photosensitive component to be added is usually reduced. According to this method, although the sensitivity is slightly increased, the under-developability is reduced. The disadvantage of further deterioration has occurred. That is, a photosensitive lithographic printing plate having excellent under-developability and high sensitivity has been desired.

[Object of the Invention] An object of the present invention is to provide a photosensitive lithographic printing plate having high sensitivity and excellent under-developability.

[Constitution of the Invention] The present inventors have conducted intensive studies and as a result, the above object of the present invention
At least (a) a polycondensation resin of 1,2-naphthoquinone-2-diazide-4-sulfonic acid, a phenol and an aldehyde or ketone, on at least a grained aluminum treatment and anodized aluminum support. This is achieved by providing a photosensitive lithographic printing plate having a photosensitive layer comprising the ester compound of (b), an acid anhydride and / or an organic acid, and (c) an alkali-soluble resin.

[Specific Configuration of the Invention] Hereinafter, the present invention will be described more specifically.

1,2-Naphthoquinone-2-diazide- in the present invention
As the 4-sulfonic acid ester compound (hereinafter, referred to as "the compound of the present invention"), various known compounds can be used. In particular, 1,2-naphthoquinone-2-diazide-4-sulfonic acid, phenols, An ester compound with a polycondensation resin with an aldehyde or ketone is preferably used.

Examples of the phenols include phenol, o
-Cresol, m-cresol, p-cresol, 3,5
-Monohydric phenols such as xylenol, carvacrol, and thymol; dihydric phenols such as catechol, resorcin and hydroquinone; and trihydric phenols such as pyrogallol and phloroglucin. Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde, and furfural. Preferred among these are formaldehyde and benzaldehyde. Examples of the ketone include acetone and methyl ethyl ketone.

Specific examples of the polycondensation resin include phenol
Formaldehyde resin, m-cresol-formaldehyde resin, p-cresol-formaldehyde resin, m
-, P-mixed cresol / formaldehyde resin, resorcin / benzaldehyde resin, pyrogallol / acetone resin and the like.

In the compound of the present invention, 1,
The condensation rate (reaction rate for one OH group) of 2-naphthoquinone-2-diazide-4-sulfonic acid is preferably from 15 to 80%, more preferably from 20 to 60%.

In addition, polyurethane resins such as 1,2
-Naphthoquinone-2-diazido-4-sulfonic acid ester compounds may also be used.

Further, as the compound of the present invention, an ester compound of a vinyl polymer having a phenolic hydroxyl group and 1,2-naphthoquinone-2-diazido-4-sulfonic acid can also be used. The vinyl polymer having a phenolic hydroxyl group that forms such an ester compound is a polymer having a unit having a phenolic hydroxyl group in its molecular structure, and is preferably a phenolic hydroxyl group used as an alkali-soluble resin described below. The same thing as the vinyl polymer which has the structural unit which has in a molecular structure is used.

As the compound of the present invention, each of the above compounds may be used alone, or two or more of them may be used in combination. The proportion of the compound of the present invention in the photosensitive composition of the present invention is preferably 5 to 60% by weight, particularly preferably 10 to 50% by weight.
% By weight.

As the organic acid used in the present invention, all known various organic acids are used, but an organic acid having a pKa value of 2 or more is preferable, a pKa value is more preferably 3.0 to 9.0, and particularly preferably 3.5 to 8.0. Organic acids are used. However, the pKa value used in the present invention is a value at 25 ° C.

Examples of such organic acids include, for example, Chemical Handbook II
(Maruzen Co., Ltd., 1966, pp. 1054-1058), all compounds that can exhibit the pKa value of the present invention can be mentioned. Such compounds include, for example, benzoic acid, adipic acid, azelaic acid, isophthalic acid, p-toluic acid, q-toluic acid, β-ethylglutaric acid, m-oxybenzoic acid, p-oxybenzoic acid, 3,
5-dimethylbenzoic acid, 3,4-dimethoxybenzoic acid, glyceric acid, glutaconic acid, glutaric acid, p-anisic acid,
Succinic acid, sebacic acid, β, β-diethylglutaric acid,
1,1-cyclobutanedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 1,1-cyclopentanedicarboxylic acid, 1,2-
Cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, β, β-dimethylglutaric acid, dimethylmalonic acid, α-tartaric acid, spearic acid, terephthalic acid, pimelic acid, phthalic acid, fumaric acid, β-propylglutaric acid , Propylmalonic acid, mandelic acid, mesotartaric acid, β-
Methylglutaric acid, β, β-methylpropylglutaric acid, methylmalonic acid, malic acid, 1,1-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3
-Cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, cis-4-cyclohexene-1,2-dicarboxylic acid, erucic acid, undecenoic acid, lauric acid, n-
Examples thereof include capric acid, pelargonic acid and n-undecanoic acid. In addition, organic acids having an enol structure such as Meldrum's acid and ascorbic acid can also be preferably used. The ratio of the organic acid in the photosensitive layer is 0.05
-10% by weight is suitable, preferably 0.1-5% by weight.

Further, as the acid anhydride used in the present invention, various known acid anhydrides are all used, but a cyclic acid anhydride is preferable, such as phthalic anhydride,
Tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-oxy - [delta ⁴ - tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, glutaric acid anhydride, maleic acid anhydride, chlorosulfonic maleic acid, alpha-phenyl maleic anhydride, And succinic anhydride, pyromellitic acid and the like. These acid anhydrides are preferably contained in the photosensitive layer in an amount of 0.05 to 10% by weight, particularly 0.1 to 5% by weight.

Various resins known in the art can be used as the alkali-soluble resin in the photosensitive composition of the present invention. In particular, a novolak resin and a vinyl polymer having a structural unit having a phenolic hydroxyl group in its molecular structure Is preferred.

Novolak resins preferably used in the present invention include resins obtained by condensing phenols and formaldehyde in the presence of an acid catalyst. Examples of the phenols include phenol, o-cresol, m-cresol, p- -Cresol, 3,5-xylenol, 2,4-xylenol, 2,5-xylenol, carvacrol, thymol, catechol, resorcin, hydroquinone, pyroganol, phloroglucin and the like. The above phenol compounds can be used alone or in combination of two or more to condense with formaldehyde to obtain a resin. Among these, a preferred novolak resin is a resin obtained by copolycondensing at least one selected from phenol, m-cresol (or o-cresol) and p-cresol with formaldehyde, for example, a phenol-formaldehyde resin , M-cresol, p-cresol,
Formaldehyde copolycondensate resin, o-cresol.p
-Cresol / formaldehyde resin, o-cresol / formaldehyde resin, phenol / p-cresol / formaldehyde copolymer resin, m-cresol / formaldehyde copolycondensate resin, phenol / m-cresol / p-cresol / formaldehyde copolycondensation Body resin, phenol, o-cresol, p-cresol,
Formaldehyde copolycondensate resins may be mentioned. Further, among the above novolak resins, phenol / m-cresol / p-cresol / formaldehyde resin is preferred.

In the present invention, the above novolak resins may be used alone or in combination of two or more.

As the molecular weight (polystyrene standard) of the novolak resin, the weight average molecular weight Mw is 2.0 × 10 ^{3 to} 2.0 × 10 ⁴ and the number average molecular weight Mn is a value within the range of 7.0 × 10 ^{2 to} 5.0 × 10 ^3. Is more preferable, and more preferably, Mw is 3.0 × 10 ^{3 to} 6.
0 × 10 ³ and Mn are values in the range of 7.7 × 10 ^{2 to} 1.2 × 10 ³ .
The measurement of the molecular weight of the novolak resin in the present invention is performed by GPC.
(Gel permeation chromatography).

Further, the vinyl polymer having a structural unit having a phenolic hydroxyl group in the molecular structure preferably used in the present invention is a polymer formed by cleavage of a carbon-carbon double bond and polymerization. Polymers containing at least one structural unit of the formulas [I] to [VI] are preferably used.

In the formula, R ₁ and R ₂ are each a hydrogen atom, an alkyl group,
Or a carboxyl group, preferably a hydrogen atom. R ₃ represents a hydrogen atom, a halogen atom or an alkyl group, preferably a hydrogen atom or an alkyl group such as a methyl group or an ethyl group. R ₄ represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and is preferably a hydrogen atom. A represents an alkylene group which may have a substituent linking a nitrogen atom or an oxygen atom to an aromatic carbon atom,
m represents an integer of 0 to 10, and B represents a phenylene group which may have a substituent or a naphthylene group which may have a substituent. In the present invention, among these, a copolymer containing at least one structural unit represented by the general formula [II] is preferable.

The vinyl polymer preferably has a copolymer type structure, and in such a copolymer,
Examples of the monomer unit which can be used in combination with at least one of the structural units represented by each of the general formulas [I] to [VI] include, for example, ethylene-based compounds such as ethylene, propylene, isobutylene, butadiene, and isoprene. Saturated olefins such as styrene, α-methylstyrene,
Styrenes such as p-methylstyrene and p-chlorostyrene; for example, acrylic acids such as acrylic acid and methacrylic acid; unsaturated unsaturated dicarboxylic acids such as itaconic acid, maleic acid, and maleic anhydride; for example, methyl acrylate, acrylic Ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, acrylic acid 2-
Esters of α-methylene aliphatic monocarboxylic acids such as chloroethyl, phenyl acrylate, α-methyl methacrylate, methyl methacrylate, ethyl methacrylate, and ethyl ethacrylate, for example, nitriles such as acrylonitrile and methacrylonitrile, for example, acrylamide Amides such as acrylanilide, p-chloroacrylanilide, m-nitroacrylanilide, m-
Anilides such as methoxyacrylanilide, for example, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyrate; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, β-chloroethyl vinyl ether, and vinyl chloride , Vinylidene chloride, vinylidene cyanide, such as 1-methyl-1-methoxyethylene, 1,1-dimethoxyethylene, 1,2-dimethoxyethylene, 1,1-dimethoxycarbonylethylene, 1-methyl-1-nitroethylene and the like Ethylene derivatives such as N
Vinyl monomers such as N-vinyl compounds such as -vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidene, and N-vinylpyrrolidone; These vinyl monomers have a structure in which the unsaturated double bond is cleaved and are present in the polymer compound.

Among the above monomers, (meth) acrylic acids, esters of aliphatic monocarboxylic acids, and nitriles may be used in combination with at least one of the structural units represented by general formulas [I] to [VI]. Shows excellent overall performance and is preferred. More preferred are methacrylic acid, methyl methacrylate, acrylonitrile, ethyl acrylate and the like.

These monomers may be bonded to the vinyl polymer in a block or random state.

General formulas [I] to [V] in the vinyl polymer
I] is 5 to 70.
Mol% is preferred, and particularly preferably 10 to 40 mol%.

The above-mentioned polymers may be used alone or in combination of two or more kinds in the photosensitive composition.

Hereinafter, typical specific examples of the vinyl polymer used in the present invention will be described. In the compounds exemplified below, Mw
Represents a weight average molecular weight, Mn represents a number average molecular weight, and s, k, o, m and n each represent mol% of a structural unit.

The proportion of the alkali-soluble resin in the photosensitive composition of the present invention is preferably from 50 to 95% by weight, more preferably from 60 to 90% by weight.

The photosensitive composition of the present invention can contain a printout material comprising a compound that generates an acid or a free radical upon exposure to light and a color-changing agent that changes the color tone by interacting with the compound.

As the compound used in the present invention to generate a free radical upon exposure, a trihaloalkyl compound or a diazonium salt compound represented by the following general formulas [VII] and [VIII] is preferably used.

(Wherein, Xa represents a trihaloalkyl group having 1 to 3 carbon atoms, W represents each atom of N, S, Se, P, C, and Z represents each of O, N, S, Se, P Y represents a non-metallic atom group necessary for cyclizing W and Z, provided that Y has a chromophore group, provided that the ring formed by the non-metallic atom group has Xa. General formula [VIII] Ar− ⁺ N ₂ X ⁻ (wherein, Ar represents an aryl group and X represents a counter ion of an inorganic compound.) Specifically, for example, a compound represented by the general formula [VII] As the trihaloalkyl compound, the following general formula [IX], [X] or [X
I] is included.

(In the formula, Xa represents a trihaloalkyl group having 1 to 3 carbon atoms, L represents a hydrogen atom or a methyl group, J represents a substituted or unsubstituted aryl group or a heterocyclic group, and n is 0, 1 or 2. )) Specific examples of the compound represented by the general formula [IX] include: Oxadiazole compounds having a benzofuran ring such as
2-trichloromethyl-5- (p-methoxystyryl) -1,3,4-oxadiazole compound described in JP-A-54-74728 or the following compound described in JP-A-60-241049 Compound: The following compounds described in JP-A-54-74728: The following compounds described in JP-A-55-77742: The following compounds described in JP-A-60-3626: The following compounds described in JP-A-60-177340: The following compounds described in JP-A-61-143748: And the like.

Specific examples of the compound represented by the general formula [X] or [XI] include 4- (2,4-dimethoxy-4-styryl) -6 described in JP-A-53-56223. −
Trichloromethyl-2-pyrone compound, JP-A-48-3628
2,4-bis- (trichloromethyl) -6-p-methoxystyryl-S-triazine compound and 2,4-bis- (trichloromethyl) -6-p-dimethylaminostyryl- And S-triazine compounds.

On the other hand, as the diazonium salt compound, a diazonium salt that generates a strong Lewis acid upon exposure is preferable,
As the counter ion portion, a counter ion of an inorganic compound is recommended. As a specific example of such a compound, the anion portion of the diazonium salt is phosphorus fluoride ion, arsenic fluoride ion, antimony fluoride ion, antimony chloride ion,
An aromatic diazonium salt which is at least one of tin chloride ion, bismuth chloride ion and zinc chloride ion is exemplified, and preferably a paradiazophenylamine salt is exemplified.

The amount of the compound that generates free radicals upon exposure to light in the total photosensitive layer composition is preferably 0.01 to 20% by weight, more preferably 0.1 to 20% by weight, and particularly preferably 0.2 to 10% by weight.

In the photosensitive composition of the present invention, as a color changing agent that changes the color tone by interacting with a photolysis product of a compound that generates an acid or a free radical upon exposure as described above, a color changing agent, a color changing agent, a color changing agent, or a color changing agent, There are two types. As the discoloring agent that fades or discolors, for example, various dyes such as diphenylmethane, triphenylmethane-based thiazine, oxazine-based, xanthene-based, anthraquinone-based, iminonaphthoquinone-based, and azomethine-based dyes are effectively used.

Specific examples of these are as follows. Brilliant green, eosin, ethyl violet, erythrosin B, methyl green, crystal violet, basic fuchsin, phenolphthalein, 1,3-diphenyltriazine, alizarin red S, thymolphthalein, methyl violet 2B, quinaldine red, rose bengal, Methanil yellow,
Thymol sulfophthalein, xylenol blue, methyl orange, orange IV, diphenylthiocarbazone,
2,7-dichlorofluorescein, paramethyl red, congo red, benzopurpurine 4B, α-naphthyl red, nile blue 2B, nile blue A, phenacetaline, methyl violet, malachite green, parafuchsin, Victoria pure blue BOH (Hodogaya Chemical ( Co., Ltd.), Oil Blue 603 [Orient Chemical Co., Ltd.], Oil Pink 312 [Orient Chemical Co., Ltd.], Oil Red 5B [Orient Chemical Co., Ltd.], Oil Scarlet 308 [Orient Chemical Co., Ltd.], Oil Red OG [Orient Chemical Co., Ltd.], Oil Red RR [Orient Chemical Co., Ltd.], Oil Green No. 502 [Orient Chemical Co., Ltd.], Spiron Red BEH Special [manufactured by Hodogaya Chemical Industry Co., Ltd.], m-cresol purple, Resole red, rhodamine B, rhodamine 6G, fast acid violet R, sulforhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, 2-carboxyanilino-4-p-diethylaminophenyliminonaphthoquinone, 2-carbostearylamino- 4-p-dihydroxyethylamino-phenyliminonaphthoquinone, p-methoxybenzoyl-p '
-Diethylamino-o'-methylphenyliminoacetanilide, cyano-p-diethylaminophenyliminoacetanilide, 1-phenyl-3-methyl-4-p-
Diethylaminophenylimino-5-pyrazolone, 1-
β-naphthyl-4-p-diethylaminophenylimino-5-pyrazolone.

Further, examples of the color-changing agent that develops a color include arylamines. Arylamines suitable for this purpose include so-called leuco dyes in addition to simple arylamines such as primary and secondary aromatic amines,
Examples of these include the following.

Diphenylamine, dibenzylaniline, triphenylamine, diethylaniline, diphenyl-p-phenylenediamine, p-toluidine, 4,4'-biphenyldiamine, o-chloroaniline, o-bromoaniline, 4
-Chloro-o-phenylenediamine, o-bromo-N, N
-Dimethylaniline, 1,2,3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, aniline, 2,5-dichloroaniline, N-methyldiphenylamine, o-toluidine, p, p'-tetramethyldiaminodiphenylmethane, N, N -Dimethyl-p-phenylenediamine, 1,2-dianilinoethylene, p, p ', p "-hexamethyltriaminotriphenylmethane, p, p'-tetramethyldiaminotriphenylmethane, p, p'-tetra Methyldiaminodiphenylmethylimine, p, p ', p "-
Triamino-o-methyltriphenylmethane, p, p ',
p "-triaminotriphenylcarbinol, p, p'-tetramethylaminodiphenyl-4-anilinonaphthylmethane, p, p ', p" -triaminotriphenylmethane, p,
p ', p "-hexapropyltriaminotriphenylmethane.

The ratio of the above-mentioned color changing agent in the photosensitive composition is 0.01%.
To 10% by weight, more preferably 0.02% by weight.
Used at ~ 5% by weight.

The photosensitive composition of the present invention may further contain a compound having at least one of the following structural units [A] and [B] in the molecular structure.

The compound having at least one of the structural units [A] and [B] used in the present invention may be any compound as long as it has one or both of the structural units [A] and [B]. However, in particular, n is an integer in the range of 2 to 5000, and a compound having a boiling point of 240 ° C. or more is preferable, and more preferably n is an integer in the range of 2 to 500 and a boiling point of 280 ° C. or more. And most preferably a compound wherein n is in the range of 3 to 100.

Examples of such compounds include: polyethylene glycol (HOCH ₂ CH ₂ OnH) polyoxyethylene alkyl ether (RO (CH ₂ CH _2
2 O) nH) ・ Polyoxyethylene alkyl phenyl ether ・ Polyoxyethylene polystyryl phenyl ether ・ Polyoxyethylene-polyoxypropylene glycol (However, including block polymer and random polymer) ・ Polyoxyethylene-polyoxypropylene alkyl ether (terminal forms alkyl ether) (Including random polymer) ・ Ethylene oxide derivative of alkylphenol formalin condensate ・ Polyoxyethylene polyhydric alcohol fatty acid partial ester ・ Polyoxyethylene fatty acid ester (for example, RCOO (CH ₂ CH ₂ O) nH) ・ Polyoxyethylene alkylamine And the like.

Specifically, for example, the following are preferable. That is, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether,
Polyoxyethylene higher alcohol ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tri Stearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbite tetraoleate, polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol monosoleate, polyethylene glycol distearate, Polyoxyethylene nonyl phenyl ether formaldehyde condensate, oxo Ethylene polyoxypropylene block copolymers, polyethylene glycol, tetraethylene glycol and the like.

The proportion of the compound having at least one of the above structural units [A] and [B] in the photosensitive composition is preferably from 0.1 to 20% by weight, more preferably from 0.2 to 20% by weight, based on the whole composition.
10% by weight.

The above compounds may be used alone or in combination of two or more as long as the content is within the above range.

The photosensitive composition of the present invention may further contain a sensitizer such as a condensation resin of an alkyl-substituted phenol and formaldehyde.

The photosensitive composition of the present invention can achieve the object of the present invention by combining the above-mentioned materials, and particularly by containing the compound of the present invention. If necessary, dyes such as dyes and pigments, sensitizers, plasticizers, and surfactants can be added.

Further, by dissolving each of these components in the following solvent and applying and drying the solution on a suitable support surface, a photosensitive layer can be provided to form a photosensitive lithographic printing plate.

Solvents that can be used when dissolving each component of the photosensitive composition of the present invention include cellosolves such as methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, ethyl cellosolve acetate, dimethylformamide, dimethyl sulfoxide, dioxane, acetone, Cyclohexanone, trichloroethylene, methyl ethyl ketone and the like can be mentioned. These solvents can be used alone or in combination of two or more.

As a coating method used when applying the photosensitive composition of the present invention to the surface of a support, conventionally known methods, for example, spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating and curtain Coating or the like is possible. At this time, the coating amount varies depending on the application, but for example, 0.5 to 5.0 g / m ² as a solid content is preferable.

As a support on which a photosensitive layer using the photosensitive composition of the present invention is provided, a metal plate such as aluminum, zinc, steel, and copper, and chromium, zinc, copper, nickel, aluminum, and iron are plated or evaporated. Examples include a metal plate, paper, a plastic film and a glass plate, paper coated with a resin, paper covered with a metal foil such as aluminum, and a plastic film subjected to a hydrophilic treatment. Of these, an aluminum plate is preferred. As a support of the photosensitive lithographic printing plate using the photosensitive composition of the present invention, it is preferable to use an aluminum plate that has been subjected to a surface treatment such as graining, anodizing, and sealing if necessary. preferable.

A known method can be applied to these processes.

As a method of graining treatment, for example, a mechanical method,
There is a method of etching by electrolysis. Examples of the mechanical method include a ball polishing method, a brush polishing method, a polishing method using liquid honing, and a buff polishing method. The above-described various methods can be used alone or in combination depending on the composition of the aluminum material and the like. Preferred is a method by electrolytic etching.

The electrolytic etching is performed in a bath containing one or more inorganic acids such as phosphoric acid, sulfuric acid, hydrochloric acid, and nitric acid.
After the graining treatment, if necessary, a desmut treatment is performed with an aqueous solution of an alkali or an acid to neutralize and wash with water.

The anodic oxidation treatment is performed by using a solution containing one or more of sulfuric acid, chromic acid, oxalic acid, phosphoric acid, malonic acid, or the like as an electrolytic solution and performing electrolysis using an aluminum plate as an anode. The amount of the formed anodic oxide film is suitably 1 to 50 mg / dm ² , and preferably 10 to 40 mg / dm ² . The amount of the anodic oxide film is determined, for example, by immersing the aluminum plate in a chromic acid phosphoric acid solution (prepared by dissolving phosphoric acid 85% solution: 35 ml, chromium oxide (VI): 20 g in 1 water) to dissolve the oxide film It can be determined by measuring the change in weight before and after dissolving the coating on the plate.

Specific examples of the sealing treatment include boiling water treatment, steam treatment, sodium silicate treatment, and dichromate aqueous solution treatment. In addition, the aluminum plate support may be subjected to an undercoating treatment with an aqueous solution of a water-soluble polymer compound or a metal salt such as fluorinated zirconic acid.

The photosensitive lithographic printing plate to which the photosensitive composition of the present invention has been applied can be subjected to development processing by a usual method. For example,
Exposure is performed through a transparent positive film with a light source such as an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp, or a tungsten lamp, and then development is performed using various alkali developing solutions. As a result, only the unexposed portions remain on the support surface,
A positive-positive relief image is formed.

Examples of the alkaline developer include aqueous solutions of alkali metal salts such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate, potassium metasilicate, dibasic sodium phosphate, and tertiary sodium phosphate. No. The concentration of the alkali metal salt is
0.1 to 10% by weight is preferred. If necessary, an anionic surfactant, an amphoteric surfactant or an organic solvent such as alcohol can be added to the developer.

[Example] (Production of aluminum plate) Aluminum plate having a thickness of 0.24 mm (material 1050, temper H16)
Was subjected to a degreasing treatment in a 5% by weight aqueous solution of sodium hydroxide at 60 ° C. for 1 minute, and then in a 0.5 molar hydrochloric acid aqueous solution at a temperature of 25 ° C., a current density of 60 A / dm ² , a treatment time of 30 seconds. Electrolytic etching was performed under the conditions. Next, 5% by weight
After a desmut treatment at 60 ° C for 10 seconds in an aqueous sodium hydroxide solution, anodizing treatment in a 20% by weight sulfuric acid solution is performed at a temperature of 20 ° C, a current density of 3 A / dm ² , a treatment time of 1 minute. Was done. Further, hot water sealing treatment was performed with hot water at 30 ° C. for 20 seconds to prepare an aluminum plate as a support for a lithographic printing plate material.

A photosensitive composition coating solution having the following composition was applied to the aluminum plate prepared as described above using a spin coater and dried at 90 ° C. for 4 minutes to obtain a positive photosensitive lithographic printing plate sample No. 1. .

(Composition of photosensitive composition coating solution) Novolak resin (1) * 1 6.8 g Compound of the present invention (QD-1) 1.5 g Tetrahydrophthalic anhydride 0.25 g 1,2-Naphthoquinone-2-diazide-4 -Sulfonyl chloride 0.08 g-Victoria Pure Blue BOH 0.06 g (manufactured by Hodogaya Chemical Co., Ltd.)-Methyl cellosolve 100 ml Further, in the above photosensitive composition coating solution composition, as shown in Table 1, the compound of the present invention and tetrahydroanhydride The photosensitive lithographic printing plate samples Nos. 2 to 8 were obtained by changing phthalic acid and appropriately changing the amounts of other additives.

A step tablet for sensitivity measurement (Eastman Kodak No. 2, gray scale of 21 steps with a density difference of 0.15 each) was closely attached to each of the thus obtained photosensitive lithographic printing plate samples No. 1 to 8, Exposure was performed from a distance of 1 m using a 4KW metal halide lamp (Iwasaki Electric Idol Fin 2000) as a light source. Next, this sample was developed at 25 ° C. for 20 seconds with a developer obtained by diluting a DP-4 (manufactured by Fuji Photo Film Co., Ltd.) developer 8 times with water. The sensitivity of the above step tablet 5.
The exposure time for completely clearing the 0 stage was expressed.

Further, in order to examine the under developability, the developability with respect to a developer having a further diluted alkali concentration, that is, a developer having a reduced developing ability was evaluated. The above developability is DP
-4 changing the dilution rate of the developer to 12 times, 13 times and 14 times,
A lithographic printing plate sample obtained by developing at 25 ° C. for 20 seconds was subjected to a printing test using Mark Five Red Ink (manufactured by Toyo Ink Co., Ltd.) at Heidel GTO, and the degree of color blemishes in the shadow area was checked. Was visually evaluated.

 Table 2 shows the obtained results.

As is clear from Table 2, photosensitive lithographic printing plate samples Nos. 1 to 6 prepared using the photosensitive composition of the present invention all had 1,2-naphthoquinone-2-diazide-4-sulfonic acid. And, compared to Samples Nos. 7 and 8 made from the photosensitive composition outside the present invention without using an ester compound of a polycondensation resin of phenols and aldehydes or ketones, any of sensitivity and under developability Excellent in properties.

* 1 Novolak resin (1) Copolycondensation resin of phenol, m-cresol, p-cresol, and formaldehyde (the molar ratio of each of phenol, m-cresol, and p-cresol is 2.0: 4.8:
3.2, Mw = 7,500, Mw / Mn = 5.0) * 2 Compound of the present invention ・ QD-6 Same as QD-3 except that Q in QD-3 is changed to Q '.

Comparative Examples 1 and 2 Instead of using tetrahydrophthalic anhydride of Example 1, benzotriazole (Comparative Example 1) and 5-nitroindazole (Comparative Example 2) described in JP-A-61-271354 were applied. Manufactured a photosensitive lithographic printing plate in the same manner as in Example 1, and performed plate making and printing. The results are shown in the table.

[Comparative Examples 3 and 4] Examples in which tetrahydrophthalic anhydride was removed from Example 1 (Comparative Example 3), and the photosensitive members of Comparative Example 3 were converted from QD-1 (substituted at position 4) to QD-6 (position 5). (Comparative Example 4) was similarly manufactured, plate-made, and printed.
It is shown in the table.

[Effects of the Invention] As described above in detail, a photosensitive lithographic printing plate having excellent under-developability and high sensitivity can be obtained by the photosensitive composition of the present invention.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Satoshi Goto 1 Konica Sakuracho, Hino-shi, Tokyo Inside Konica Corporation (72) Inventor Hiroshi Tomiyasu 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Chemical Corporation In-house (72) Inventor Yoshiko Kobayashi 1000 Kamoshita-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsubishi Chemical Research Institute (56) References JP-A-61-107353 (JP, A) JP-A-61-203449 (JP, A) JP-A-61-271354 (JP, A) JP-A-58-11932 (JP, A) JP-A-61-7837 (JP, A) JP-A-62-105137 (JP, A) JP-A Sho 52 -8022 (JP, A) JP-A-62-150354 (JP, A)

Claims (1)

(57) [Claims] (1) At least a grained and anodized aluminum support is provided on an aluminum support.
(A) an ester compound of 1,2-naphthoquinone-2-diazido-4-sulfonic acid and a polycondensation resin of a phenol and an aldehyde or ketone; (b) an acid anhydride and / or an organic acid; and (c) ) A photosensitive lithographic printing plate having a photosensitive layer containing an alkali-soluble resin.